Author: Qin, Yiang
Title: Optically 3D μ-printed whispering-gallery-mode microresonators for fluorescence spectroscopy biosensing
Degree: M.Sc.
Year: 2023
Subject: Lasers
Lasers -- Resonators
Hong Kong Polytechnic University -- Dissertations
Department: Department of Electrical Engineering
Pages: 71 pages : color illustrations
Language: English
Abstract: The WGM optical microcavity is a very popular microcavity nowadays and a very promising research direction. It originates from the phenomenon of echoes in the circular domes of European cathedrals. Like the propagation of sound, light can accomplish continuous reflection and propagation in a similar structure. The WGM microcavity is a resonant cavity and therefore has the potential to make micro and nano lasers, while the higher Q value gives it the potential to be applied as a high sensitivity sensor. This paper will detail the use of our laboratory's mask-less 3D µ-printing technology to prepare WGM microcavities using SU-8 polymers on glass substrates and coated with gain media to produce micro-lasers. There are now many studies on WGM microcavities, while this paper has focused on the fabrication of WGM microcavities. Our fabrication method uses SU-8 resin, which has low optical loss and high mechanical strength compared to other polymers. Our exposure system is based on a DMD mask-less 3D UV printing technology, which allows for more efficient production of WGM microcavities at a lower cost. In addition, we have introduced a micro-laser, which is coated with a gain medium on the WGM microcavity to form a laser, reducing the difficulty of coupling and the difficulty of spectral analysis during detection. This allows for easy integration on microfluidic chips and as sensor devices for bioassay applications in future.
The first chapter of this paper will provide background on the WGM microcavity and its exciting performance in various areas. Chapter 2 of this paper will focus on the theoretical basis and basic concepts related to WGM microcavities and introduce the ideas of designing microcavities and the simulation process. Chapter 3 is the core chapter of this paper and will provide a complete and detailed description of the process and procedures used to prepare the WGM microcavities in our laboratory. Chapter 4 will describe our test platform, the test process, and the final test results. Chapter 5 will summarize the full text and provide suggestions and ideas for future improvements and developments.
Rights: All rights reserved
Access: restricted access

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Please use this identifier to cite or link to this item: https://theses.lib.polyu.edu.hk/handle/200/13107